It is proposed that Prof. James J. Mason, from the Aerospace and Mechanical Engineering Department at the University of Notre Dame, spend a one year sabbatical at the Indiana University School of Medicine in Indianapolis working with Dr. Charles Turner in the area of bone biology. The focus of the research will be cellular response to mechanical loading. Specifically, Dr. Mason will perform experiments investigating the combined effect of matrix strain and fluid flow on osteoblast activity in various regions within a dynamically loaded 3D collagen matrix. In these experiments, the level of fluid flow within the matrix will be estimated by observing the movement of microspheres in the fluid. The experiments will be augmented by finite element models of the collagen matrix and fluid to quantify the level of local fluid flow and matrix strain.